fig4

Figure 4. (A) A small chemical against far upstream element-binding protein-interacting repressor Δexon2 screened by natural product depository array at RIKEN (Wako city, Saitama, Japan). Two compounds showed inhibitory activity [(B) and (B')] in the cell-based assay. The conformation of the two inhibitory compounds was found to resemble the WD motif (C); Hence, from the similarity to the chemical structure of WD-like motif, we tested several compounds that had been already synthesized in our previous studies targeting viral proteins. Based on the tests with the synthesized compounds, we modified the chemical structure and finally identified BK697 (D). WD: W (Typ) D (Asp)